DALLAS (CBSDFW.COM) – Federal prosecutors said agents recently liberated dozens of women who were sold for sex in Dallas after an undercover sting operation.

A grand jury indicted 58-year-old Helen Kim on federal racketeering charges.

Prosecutors said she operated the Pink One and Illusion spas in Dallas, and that they “were actually fronts for providing commercial sex to customers.”

“The defendant’s willingness to demean women for financial gain is sickening,” said Erin Nealy Cox, the U.S. Attorney for the Northern District of Texas. “We cannot and will not allow this type of behavior to go unchecked in North Texas.”

The U.S. Attorney’s Office in Dallas said 50 members of the Dallas Police Department, Texas Department of Public Safety, and Homeland Security Investigations posed as out of town businessman who were prepared to pay for sex.

The indictment said Kim’s son told one undercover officer “it could be considered human trafficking.”

Bill Bernstein is with Mosaic Family Services, which has helped hundreds of trafficking victims.

“When we say human trafficking, we’re really talking about a form of modern slavery,” said Bernstein.

According to the indictment, Kim offered the undercover agents 20 women who would provide the “girlfriend experience,” which is sex without a condom, for a total of $40,000 dollars for four hours.

Prosecutors said she accepted a $5,000 down payment weeks before being paid the remainder of the cash.

According to court documents, she discussed with agents whether the customers would need cocaine, erectile dysfunction drugs, and the number of times they wanted to have sex.

Prosecutors said some of the victims from the spas went to a shelter run by Mosaic.

Bernstein would not confirm that, but says in general, victims can suffer from PTSD.  “Very often when people are leaving these situations where they’ve experienced severe trauma, their brain is not functioning clearly and the ability to tell a coherent, straight-line story is very challenging.”

Bernstein credits the Dallas Police Department, the U.S. Attorney’s Office, and the Texas Department of Public Safety for pursuing these types of cases.

“Over the last couple, three years, we’ve really seen a steady increase in the number of referrals of people that are being trafficked,” said Bernstein. “These referrals are coming from the community.”

In court Friday, Kim pleaded not guilty to the racketeering charges and if convicted she will face up to five years in prison.

No trial date has been set yet.

Prosecutors said they have seized assets from Kim’s home and spas.